Grate for industrial furnaces

ABSTRACT

A grate, particularly of the type used for removing waste material from large industrial furnaces, which comprises a movable, biased transfer grate element between a fixed grate element and a rotary grate element. The transfer element is in sliding contact with the rotary grate element.

United States Patent 72] Inventor Johannes Josef Martin [50] Field ofSearch .l 110/33, 39,

Leopoldstrasse 248, Munich 23, Germany 35; 126/174, 181 [21 App]. No.811,765 22 Filed Apr. 1,1969 References cued 45] Patented May 25, 1971UNITED STATES PATENTS [32] Pnorrty Apr. 6, 1968 1,804,638 5/1931Musshart 110/33 Germany 3,469,544 9/1969 Kremer 110/35 [54] GRATE FORINDUSTRIAL FURNACES 11 Claims, 1 Drawing Fig.

[52] US. Cl 110/35, 126/181 [51] Int. Cl F23b l/24 PrimaryExaminer-Edward G. Favors Attorney-Michael S. Striker ABSTRACT: A grate,particularly of the type used for removing waste material from largeindustrial furnaces, which comprises a movable, biased transfer grateelement between a fixed grate element and a rotary grate element. Thetransfer element is in sliding contact with the rotary grate element.

GRATE FOR INDUSTRIAL FURNACES BACKGROUND OF THE INVENTION The presentinvention relates to grates, more particularly to improvements in gratesused for the removal of waste material from large industrial furnaces.Still more particularly, the invention relates to improvements in grateswhich employ a combination of grate components at least one of which ismovable to effect such removal.

For example, a presently known construction embodies a fixed grateelement and a movable final discharge or conveying element, there beingan aperture between the two ele ments to allow clearance for thedischarge element to move. During the heat treatment of the materialthat passes through the furnace ashes, cinders, slag or scale whichdevelop in connection with such heat treatment are deposited on aninitial grate element and are transferred by mechanical means to thefixed grate element whereupon the waste material is further depositedonto the movable discharge elementwhich discharges the waste into adischarge chute.

A disadvantage inherent in this type of grate construction is that somewaste material often falls into the aperture in front of the dischargeelement, rather than onto the discharge element.

SUMMARY OF .THE INVENTION It is an object of this invention to provide anovel grate means for removing waste material from large industrialfurnaces.

Another object of this invention is to eliminate the drawbacks ofpresently known grates used to remove waste material from largeindustrial furnaces through the use of a continuous grate of improveddesign and construction.

Another object of this invention is to provide a grate which efficientlycontrols the transport of waste material in large industrial furnaces.

The improved grate comprises a first grate member, a driven second gratemember which defines a gap with the first member and a third gratemember which bridges the gap between the first and second members. Thethird grate member is movable with reference to the first and secondmembers and abuts the second member.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved grate itself, however, both as to its construction and itsmethod of operation, together with additional features and advantagesthereof, will be best understood from the following description ofspecific embodiments when read in connection with the accompanyingdrawing.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE is a schematicsectional view of a preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the single FIGUREthere is shown a first grate member, grate bar 1, a second grate member,discharge drum 2, which defines a gap with the first member, and a thirdgrate member, intermediate grate bar 5 which bridges the thus formedgap. Furnace frame 9 includes as a part thereof a support means for bar5 shown by pivot 3. One end of bar 5 is articulately connected to thepivot 3, which has a horizontal axis, in such a manner that bar 5 ismovable in a vertical direction which is substantially normal to theaxis of pivot 3. The other end of bar 5 is in the form of a roundedportion 4 which abuts against the external surface of drum 2. Drum 2 isdriven to rotate about an axis which is substantially parallel to theaxis of pivot 3 in a direction indicated by the arrow by means of shaft10 which is coupled to a not shown prime mover. The external surface ofdrum 2 comprises a series of projections or ripples 8. As drum 2 isrotated in the direction shown, end portion 4 of bar 5 bears against thesurface of drum 2 at a point above the axis of drum 2 by reason of theweight of bar 5. Bar 5 follows the contour formed by ripples 8 in amanner analogous to that of the movement of a cam and follower. Thusripples 8 on drum 2 impart periodic motion to bar 5 causing it to movein an oscillatory manner about pivot 3 while it remains in constantsliding contact with the surface of drum 2 in the region where suchsurface travels upwardly.

This arrangement of intermediate bar 5 between grate bar 1 and drum 2forms a continuous path for the transfer of waste material practicallywithout apertures or spaces between these components. A significantadvantage of this construction is that by eliminating the gaps betweenthe components, the waste material such as ashes, cinders, slag or scalecan be transferred in a more efficient manner than has been possiblewith presently known grate constructions. This is because whateverclearances may still exist between the individual components do notallow an appreciable amount of waste material to passthrough. It ispossible to further reduce the likelihood of material loss between thegrate members 1 and 2 by adding a biasing means to control the contactpressure of bar 5 against the peripheral surface of drum 2. For example,

and as shown in the drawing, the biasing means can include a connectingmember 6 which is pivotally connected to bar 5 as shown at 60, while theother end is resiliently .mounted to frame 9 by means of an adjustablespring means 7. By varying the biasing force of spring means 7, thetension of member 7 acting upon bar can be increased or decreased,thereby varying the contact pressure of bar 5 against drum 2 in additionto or detraction from the already existing contact pressure whichresults from the weight of bar 5.

The present invention serves to provide a number of advantages over theprior art in that:

1. The waste material is efficiently transported to a predeterminedlocation to the right of drum 2 in the FIGURE.

2. The waste material cannot fall between grate members 1 and 2 eventhough-there may be a substantial gap between them.

3. The accumulation of waste material can be more easily controlled toensure that there will be no interference'with the rotation of drum 2.

4. The novel intermediate grate bar 5 does not interfere with therotation of drum 2, despite the fact that bar 5 bridges the gap betweengrate members 1 and 2.

5. Rotation of drum 2 can be utilized to impart periodic motion to bar 5and thereby aid in the efficient transfer of material from bar 1 to drum2.

6. Such efficient transfer of the waste material is facilitated by thefact that the upper sides of grate bars 1 and 5 slope respectivelydownward toward grate bar 5 and drum 2.

Without further analysis, the foregoing will so fully reveal .the gistof the present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of the above-mentioned contribution to the art.

lclaimz.

1. A grate, particularly for use in large industrial furnaces,comprising a first grate member; a driven second grate member having anaxis and a surface about said axis and being rotatable in one directionabout said axis, said second grate member defining a gap with said firstgrate member; a third grate member bridging the gap between said firstand second members, said third grate member being movable with referenceto said first and second members and abutting said surface of saidsecond member during rotation of the latter about its axis.

2. A grate as defined in claim 1, wherein said rotatable second gratemember comprises a drum rotatable about a substantially horizontal axis,said third grate member abutting with one end thereof against theperipheral surface of said drum and being mounted at the other endthereof for pivotal movement about an axis substantially parallel tosaid drum axis.

3.'A grate as defined in claim 2, wherein said one end of said thirdgrate member is rounded.

4. A grate as defined in claim 2, wherein said third grate member bearsby gravity against said second grate member.

5. A grate as defined in claim 2, further comprising support means forsaid third grate member.

6. A grate as defined in claim 5, further comprising a frame includingsaid support means, said support means comprising a pivot having asubstantially horizontal axis. 7

'7. A grate as defined in claim 6, wherein said third member has an endportion articulately connected to said pivot and movable in a directionwhich is substantially normal to said axis.

8. A grate as defined in claim 2, further comprising means for impartingperiodic motion to said third grate member.

9. A grate as defined in claim 8, wherein said means for impartingperiodic motion to said third grate member comprises projections on theexternal surface of said second grate member.

10. A grate, particularly for use in large industrial furnaces,comprising a first grate member; a driven second grate member defining'a gap with said first member; a third grate member bridging the gapbetween said first and second members, said third grate member beingmovable with reference to said first and second members and abuttingagainst said second member; and biassing means for urging said thirdgrate member against said second grate member. 7

11. A grate as defined in claim 10, wherein said biasing means comprisesa-connecting member secured to said third grate member, a frame, andresilient means operating between said frame and said connecting memberto urge said third member against said second member.

1. A grate, particularly for use in large industrial furnaces,comprising a first grate member; a driven second grate member having anaxis and a surface about said axis and being rotatable in one directionabout said axis, said second grate member defining a gap with said firstgrate member; a third grate member bridging the gap between said firstand second members, said third grate member being movable with referenceto said first and second memberS and abutting said surface of saidsecond member during rotation of the latter about its axis.
 2. A grateas defined in claim 1, wherein said rotatable second grate membercomprises a drum rotatable about a substantially horizontal axis, saidthird grate member abutting with one end thereof against the peripheralsurface of said drum and being mounted at the other end thereof forpivotal movement about an axis substantially parallel to said drum axis.3. A grate as defined in claim 2, wherein said one end of said thirdgrate member is rounded.
 4. A grate as defined in claim 2, wherein saidthird grate member bears by gravity against said second grate member. 5.A grate as defined in claim 2, further comprising support means for saidthird grate member.
 6. A grate as defined in claim 5, further comprisinga frame including said support means, said support means comprising apivot having a substantially horizontal axis.
 7. A grate as defined inclaim 6, wherein said third member has an end portion articulatelyconnected to said pivot and movable in a direction which issubstantially normal to said axis.
 8. A grate as defined in claim 2,further comprising means for imparting periodic motion to said thirdgrate member.
 9. A grate as defined in claim 8, wherein said means forimparting periodic motion to said third grate member comprisesprojections on the external surface of said second grate member.
 10. Agrate, particularly for use in large industrial furnaces, comprising afirst grate member; a driven second grate member defining a gap withsaid first member; a third grate member bridging the gap between saidfirst and second members, said third grate member being movable withreference to said first and second members and abutting against saidsecond member; and biassing means for urging said third grate memberagainst said second grate member.
 11. A grate as defined in claim 10,wherein said biasing means comprises a connecting member secured to saidthird grate member, a frame, and resilient means operating between saidframe and said connecting member to urge said third member against saidsecond member.